CaCO₃/Tetraethylenepentamine-Graphene Hollow Microspheres as Biocompatible Bone Drug Carriers for Controlled Release

CaCO₃ is one kind of important biological mineral, which widely exists in coral, shell, and other organisms. Since it is similar to bone tissue elements and has good biocompatibility, it was very suitable as a candidates for bone drug carriers. In this work, we used tetraethylenepentamine-graphene (rGO-TEPA) sheet matrices induction of CaCO₃ mineralization and successfully constructed CaCO₃/rGO-TEPA drug carriers with a hollow structure and rough surface. As potential drug carriers, doxorubicin (DOX) loading and release measurements were carried out. It showed that load efficiency was 94.7% and the release efficiencies were 13.8% and 91.7% at values of pH 7.4 and 5.0. The as-prepared drug carriers showed some appealing advantages, such as the pH-sensitive release characteristics and mild storage-release behaviors. The excellent biocompatibility and nontoxicity of CaCO₃/rGO-TEPA hybrid microspheres were tested by the cell viability of mouse preosteoblast cells (MC3T3-E1). And cytotoxicity with human osteosarcoma cells (MG-63) was carried out to demonstrate the drug release effect in the cells system. Therefore, the CaCO₃/rGO-TEPA hybrid microspheres would be a competitive alternative in bone drug carriers.